Thermostat



March 2; 1937. M. GAUL THERMOSMTv Filed Nov.v 19, 1934 n Patented Mar. 2, 1937 UNITED STATES PATENT GFFICE Application November 19, 1934, Serial No. 753,718

In Germany September 19, 1933 2 Claims.

This invention relates to thermostats in which a bellows-like container usually made of copper is used, which is expanded and contracted owing to temperature variations of the liquid therein. It is known to make use of this phenomenon for operating a throttle flap or. the like in pipes lled with a liquid, steam or gas with the object of keeping the temperature at a definite height or within deiinite limits. One disadvantage of this l0 arrangement is, that the thermostatic element fills the' greater part of the cross-section of the pipe and consequently has a disturbing eect on the flow, if, having regard to the available space, for instance in the case of motor vehicles, the pipe cannot be made of any desired cross-section. Furthermore the effect of the flowing liquid on the thermostatic element is, owing to the xed position of the latter, not always entirely favourable. `Accorcling to the present invention the thermostatic element is itself used as the valve or throttling flap, thus combining a very simple constructional form of the whole device with the best possible effect of the owing or stationary liquid and the like on the element in any position.

A constructional example of the inventionis illustrated' ln the accompanying drawing. in which Fig. l is a side elevation; Fig. 2 a part section 3o on line A--A of Fig. 1; Fig. 3 a side elevation as in Fig. 1, with the thermostatic element in another position, and Fig. 4 a plan view.

The flange Lof thick metal sheet is designed for mounting the thermostat, for instance in the cooling water pipe of motor vehicles. At two oppositely located places of the aperture in the liange l for the passage of the cooling water two lugs 2 are bent out at right anglesfrom the metal sheet, which serve as bearing supports for the thermostatic element 3 consisting of a copper bellows body ol a known kind, which is closed on all sides and is iilled with the liquid. For this purpose'its base plate 4 is provided with two oppositely located upwardly bent lugs 5.'

with the bores in which the element 3 can turn about the iixed axial pins 0. These pins form eccentrically projecting parts 4of discs 1 which arev fixed in the bearing supports 2 by soldering or riveting. There are further mounted on the 50 crank members 8 which are controlled by pins I0 xed on the cover plate 9 of the thermostatic element 3. The cover plate 9 acts as the valve plate and is consequently made somewhat larger discs l so asto be 'capable o; turning on them thai. the passage aperture provided in the flange l I. As the plate 9 -by turning about the pins 6 lifts from the flange I (Fig. 3), the latten-engages with the edge of the aperture on one side (in Figs. 1, 3, 4 on the left) over the plate 9 and on the opposite side under it. The thermostat which is inserted for instance in the cooling water pipe of a motor vehicle operates as follows: When .the cooling water is below a certain temperature the aperture in the flange l leading to the radiator is closed by the cover plate 9 of the thermostatic element 3. As the temperature rises the cooling water circulates in the by-pass pipe and in iront of the closed aperture, sweeping over the folds of the element 3 in a very effective manner. This continues until the cooling water has reached a temperature at which the liquid in the element vapori'zes and thereby causes the bellows body 3 to expand. This `expansion which develops a great force necessarily causes the two positively connected points of revolution 6 and l0 on the thermostatic element to move apart out of their initial position by the amount of the gradual expansion of the bellows body 3. The element can thus gradually swing from the initial position shown in Fig. 1 into the extreme position shown in Fig. 3. The greatest possible expansion of the bellows body 3 and the eccentricity of the two pivotal points 6 and l0 are thus in a xed ratio to the right angle enclosed by the extreme positions of the thermostatic element so that a rotation beyond the right angle is impossible. Regarded as a valve plate, the thermostatic element provides in its position according to Fig.` 3 the greatest passage of iiow for the cooling 'water and the latter will again sweep over the folds of the bellows body, that is to say the cooling surface, in a. very effective manner, so that the most rapid transmission of heat from'the cooling water to the liquid in the element (from that which is to be regulated to that which regulates) is ensured and consequently the thermostat acts with as little inertia as possible.

e invention, that is the employment of the thermostatic element as an integral part of the valve and at the same time as a driving means for the valve, is not limited4 to the constructional form here described which can be modied in e many ways. More particularly the mechanical motion imparting members for the element are capableof various modications.

What I ,claim is:

1. 'I'he combination of a valve mounting with a thermostat element adapted to expand and contract lengthwise under variations in temperature. a ilat valve disc secured to one end of the thermostat element so as to leave the remainder 2. The combination of a valve mounting with a thermostat element adapted to expand and contract lengthwise under variations in temperature, a ilat valve disc secured to one end oi the thermostat element so as to leave the remainder of the thermostat element fully exposed, pivots fixed on said valve mounting, levers mounted on said pivots and having pins thereon xed to the valve disc for rotatably supporting one end of the thermostat element on the valve mounting.

. and eccentric axial pins on said pivots for rotatably supporting the other end of the thermostat element on the valve mounting, said pivots being located intermediately of the ends of the thermostat element so that on the thermostat element expanding it is forced to turn bodily around the said pivots and axial pins.

MAX GAUL. 

